Congressional District Data

Scope of the data

The data set
includes a wide range of economic, social, and geographic information for every
U.S. congressional district, from 1943-1998. The variables range from
such basic information as size of each district (in square miles), the
population, and the number unemployed (at the time of each census) to much more
specialized information like the number of beds in Veterans
Administration/Dept. of Veterans Affairs hospitals in the district or whether
the district is coastal (see codebook for variable descriptions). Most of
the data are specific to each congressional district, but occasionally I have
included state-wide data where district-level information was unavailable.

District data
were collected once every ten years, with the exception of instances where
district lines were redrawn mid-decade and new census data were available
(these reapportioned districts are noted in each data file where they
appear). Normally, redrawn districts become effective at start of the new congressional term immediate following the availability of the new census data (usually in the
third year of each decade [e.g., 1953, 1963, etc.,). In several instances
variables do not exist for every decade do to lack of availability of information.
I have included a table that lists which variables exist in each decade.

Data sources

A large
portion of the data come from the decennial census. Data from the
1960-1990 censuses were aggregated by congressional district in the Congressional
Data Books and associated data files. For the prior decades, county-level
census data were aggregated into congressional districts (see description
below).

Several
variables in this data set were not contained in the census and had to be
collected individually. The non-census data come from a variety of
sources that are listed in the codebook. When sites such as military
installations or VA hospitals needed to be placed into their appropriate
districts, this was accomplished using an assortment of census Congressional
District Atlases; Congressional Directories; Congressional Quarterly’s
Congressional Districts in the 1970s, 1980s, and 1990s; Rand McNally Road
Atlases; military road atlases; U.S. Geological Survey maps; and maps of
congressional districts in the 1940s and 1950s provided from a private
collection.

Aggregation Procedure for 1940s and 1950s Census Data

Data from the
1940 and 1950 censuses were available only at the county-level. To
construct district-level data for “whole-county” districts (districts entirely
composed of one or more whole counties), county-level information was
aggregated into congressional districts using a combination of maps and
descriptions of congressional district boundaries published in the
Congressional Directories and Kenneth Martis’s, The Historical Atlas of United States
Congressional Districts, 1789-1983 (New York: Free Press, 1982).

For
counties that were divided into several congressional districts (primarily
those comprising large cities), or partitioned into districts that contained
part of more than one county, I employed a system of data aggregation that
utilized the Census’s Congressional District Atlas for 1960 (which contained
the boundaries of districts for the pre-1962 districts) and Michael Dubin’s
detailed maps of congressional districts. Urban counties that contained
multiple congressional districts were divided geographically and
demographically according to the respective number of districts. For
example, the proportion unemployed in Los Angeles County in the 1950s was
utilized as the proportion unemployed in the 15th through 26th congressional
districts of California, which encompassed the county in that decade. In
several instances counties were divided among two congressional districts, but
these county portions only made up part of an entire district. In such
cases the sum of the population of all the other counties in the district was
subtracted from the population of the entire district (as provided in the
Congressional Directory) to estimate the population contained in the divided
county, and thus the proportion of the county within that district.